Hi @learningtofly79 ,
I'm afraid that is not available, but here is a workaround for your reference:
1\Create a SharePoint list
2\Add a 'create item' action in flow to create an item before send the approval.
3\Ge the item link created in step 2 and then send an approval with the item link.
4\If the approver wants to add an attachment , he could navigate to the SharePoint list item and add an attachment by clicking the item link.
Best Regards,
Bof
